Tube forming machine



June 11,v 1946- H. R. GILLETTE Erm.

TUBE FORMI'NG MACHINE i Filed July 2, 1942V 7 SheetS-Sheet 1 June l-l, 1946- H. R. GILLETTE ET Al.

TUBE FORMING MACHINE Filed July 2, 1942 sheets-sheet 2 `lune ll, 19,46.

H. R.v GILLTTE x-:TAL

TUBE FQRMING -MAGHINE Filed July-2, 1942 'I sheds-,sheet s June 11, 1946.

H. R. GlLLl-:TTE ETAL TUBE FORMING MACHINE Filed 'July 2, 1942 '7 Sheets-Sheet 4 June 11, 1946. H. R. GILLETTE :TAL 2,401,728

TUBE FORMING MACHINE Filed July '2, 1942 7 sheets-sheet 5 .QRNLW W mq y@ m. N. m .5@ w

2! j fihi.'

TUBE FORMING MACHINE '7 Sheets-Sheet 6 Filed July 2 1942 H. R. GILLETTE ETAL 2,401,728

TUBE FORMING MACHINE Filed July 2, 1942 7 Sheets- Sheet 7 June ll, 1,946.

ifo-P119? mei NQ RENS: wwhm.

Patented June 11, 1946 TUBE FoRMING MACHINE Harold`R. Gillette, Boston, Mass., Carl J. Kopp, Chicago, Ill., and Robert S. Gillette, Springfield, Vt., assignors to Federal Electric Company, Inc., Chicago, Ill., a corporation of New York Application July 2, 1942,'Seral No. 449,466

9 Claims.

This invention relates to improvements in a machine for pressing plastic'articles, and relates specifically to a means for pressing and forming brous tubes or 'pipes the walls of Which carry a plastic binder which is caused to flow and set during the pressing operation.

An important feature of the invention resides in an apparatus which is of comparatively simple construction and can be quickly and conveniently operated to press and compact the walls of fibrous tubes.

A further important feature of the invention resides in the unique four-piece outer dies embodied in the apparatus, so arranged and constructed as to function simultaneously and impart a uniform pressure to the outer cylindrical walls of the tube being pressed and compacted.

Another important feature of the invention resides in the construction of the mandrel upon which the tube or pipe is formed, and` specifically the means for uniformly heating and chilling the mandrel throughout its entire length.

Other objects, advantages and aspects of the invention willbe apparent from the accompanying drawings and following detailed description.

In the drawings,

Fig. 1 is a side elevational view of the pressing machine comprising the present invention.

Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is an end elevational view looking-in the direction of the arrows 3-3 of Fig. 1.

Fig. 4 is a plan sectional view of the machine taken on the line 4-4 of Fig. `1.

Fig. 5 is a. plan sectional view taken through one of the dies.

Fig. 6 is a detailed transverse sectional view taken on line B-S of Fi'g. 1, showing the dies in closed or Dressing position.

Fig` 7 is a similar view showing the dies in apen position and further illustrating the stripping mechanismI in operative position.

Fig. 8 is a detailed longitudinal sectional view important 2 Fig. 12 is a transverse sectional view taken on line I2-I2 of Fig. l1. i

Fig. 13 isa diagrammatic vieW of a portion of the piping system for the machine.

Referring in detail to the drawings, :and pary tlcularly Figs. 1, 2 and 3 thereof, l indicates a transverse supporting 'memben a. plurality of which are employed constituting the foundation of the press. 'Iwo channel irons 2, each mounted on edge, are positioned in' spaced parallel relationship upon the. supporting members I, the

' channel irons traversing substantially the length taken through both the upper and lower dies,

showing a pipe being pressed.

Fia-9 is a fragmentary perspective view of a rolled brous pipe preliminary to pressing.

Fig. 10 is a development view of a. fibrous sheet from which thepipe shown in Fig. 9 is formed. y

Fig. l1 is a fragmentary sectional view taken through a portion of the mandrel.

Fig. 11a is a continuation of the view .shown n FIZ. 11.

ofthe press.

A plurality of hydraulic cylinders 3 are mounted upon the channels 2, one cylinder being positioned between each two 4adjacent supporting members I. The cylinders 3 carry transverse extensions 4 which rest upon the channels :and may be secured to said channels by welding or other suitable means of attachment. A piston rod or ram 5 is slidably positioned in each-cylinder, be-

ing carried by a piston (not shown) in each cylinder, whereby said rams may be raised or lowered hydraulically. as desired. .'Ihe hydraulic connections to the cylinders 3 are not shown, but are of conventional construction and, in themselves, constitute no part of the present invention.

A platen 6 is carried upon the feet of the rams 5 and extends longitudinally of the machine whereby simultaneous movement of the rams functions to uniformly raise or lower the platen.

4A rotatable shaft 1 lournalled in bearing blocks 8 extends throughout the length 0f the machine and at each end carries an arm 9. Each arm 9 is pivotally connected to a connecting rod I0 and each of the latter is, in turn, pivotally connected to an end of the platen 6. By the'provision of shaft 1, arms 9 and connecting rods I0 uniform vertical movement of the platen is assured.

A pair of spaced tie rods I I extend upwardly from each supporting member I, said rods carrying threads I2 adjacent their upper ends. A cross support I3 is carried by each pair of tie rods, each of said supports being confined' between nuts Il and I5 threaded upon the rods II, the arrangement being such as to permit a limltedvertical adjustment of the cross-supports upon the tie rods. A pair of channel irons I6 depend-from the cross-supports, said channels being spaced from each other and disposed longitudinally oi? the machine. the flanges of the channels being welded or otherwise suitably secured to the cross-supports. The opposite flanges of the .channels` I8 are suitably secured `to an upper platen Il 3 which extends longitudinally' of the machine immediately above the lower platen 5.

'I'he lower platen 5 carries a lower die I8 which has projectingfrom the lateral sides thereof lugs I9 which are spaced from eachother along the length of the die. A plurality of clamps 20 are secured to the platen 5 by means of screws 2I,

said clamps having overhanging' portions 22 whichv embrace the spaced lugs I9, the arrangement duced into the sections 34 and 35. Fittings 44 I8 with respect to the platen 6 is permitted whereas lateral and vertical relative movement is prevented. At one end of the die 6 a pair of anchor plates '23, one on each side of the die, rigidly anchors the die to the platen. Throughout the length of the die, howeverI and at the opposite end of the .die relative longitudinal movement of the die and platen is permitted, due, as will be hereinafter'more fully described, to heating and cooling of the die.

An upper die 24 is carried upon the lower surface of the upper platen I1, said die being provided with a plurality of laterally projecting lugs 25 whichare spaced from each other along each. side of the length of the die. Clamps 25, secured to the platen Il by means of screws 2l, function to confine the lugs 25, said clamps being provided with overhanging portions 28, the arrangement being such that the die 24 is held immovable latand 45 connect the opposite ends of the sections 35 and 34 to the ends of sections 36 and 33 respectively whereby fluid introduced into the sections 34 'and 35 is passed into the sections 33 and 36 respectively. A pipe 45 connects into the opposite end of the section 33 and a pipe 4.1 connects into the opposite end of the section 36. both of said pipes connecting into a header 4B which in turn connects with a drain 49 whereby the liquid introduced through the inlet pipe 43 passes throughthe various sections of the die and is discharged through the, drain 49.

It is to be understood, Vof course, that the uid number of ttings similar to'fittings 44 and 45 erally and vertically with respect to the platen I1, but is permitted to move longitudinally. A.v

pair of spacedA sleeves lllA are secured to a lateral wall of the platen I1 adjacent one end thereof. said sleeves being internally threaded to receive adjusting screw 30. A sleeve 3l is adapted to threadedly engage an intermediate portion of screw 30, said sleeve having an inwardly projecting lug portion 32 which is secured to the opposite lateral walls of the die 24. The arrangement is such that by manipulation of the screws 30 on each side of the platen, the die 24 may be adjusted longitudinally with respect to the platen 'and also with respect tothe lower die I8.

It can readily be seen that the upper die 24 is anchored at one end only and the intermediate portion of said die and the opposite end thereof is free to move longitudinally when subjected to variations in temperature.

The dies I8 and 24 are of hollow construction as shown best in Figs.: 5, 6, 7 and 8 whereby a heating or cooling fluid may be introduced into the interior of saiddies. Each of the dies is preferably constructed in a plurality of sections as indicated at 33, 34, and 35 in Fig. 5. It is to be understood, of course, that the upper and will be employed. 1f the total die length is comparatively short, the fluid may be introduced at one end of the die and discharged at the opposite end thereof without materially causing a wide degree of temperature differential between the opposite ends of the die. Asavill be hereinafter more fully appreciated, it is desirable that the lower dies I Sand 24,#if desired, may be constructdies be maintained uniform in temperature throughout their entire length and throughout their entire pressing surface.

' The juxtaposed faces of the dies I8 and 24 are concave, as shown best in Figs. 6 and '1. The longitudinal central portion of each of the concave surfaces of the dies is constructed along the arc of a, circle, the transverse section of said dies l .being substantially circular throughout an arc of about 45 on each side of the longitudinal center line of the dies. The cylindrical arced surface of the dies is then carried along a substantially tangential line at an angle of about 45. Thus, it can be seen that the pressing surfaces notches and beingsecured by means of screws |512` o rigidly to the die I8. The plates 5I are co-extensive with the llength of the die I3 and project illustrated in Fig. 5, each of the sections being upwardly therefrom. Each of the plates 5I is provided with a plurality of spaced transverse slots 53 which open to the upper surfaces of the plates. A bolt 54 is positioned in each of the t slots 53 and carries at one end an auxiliary die section 55. The die section 55 is provided with -a concave outer surface 55 which substantially washer being normally urged into contact with .the outer surface of the p late5l by means ,of'coil spring 59, the opposite end of which abuts against washer 50 which is maintained at a predetermined position upon bolt 84 by means of nuts 6I.V The arrangement is such that the bolts 54 and hence the auxiliary die sections 65 are resiliently movable inwardly and outwardly with respect to the plates 6I.

In operation, when the lower platen 6 is moved upwardly by the action of the rams 5, the tangential surface portions of the upper die contact the outer angular faces 51 of the upper portions of the auxiliary'die sections 55. In so contacting the faces 51 of the auxiliarydie sections j arrangement is such that as the upward motion of the die I8 continues, the downward and inward motion of the bolts 54 eventually ceases, at which time 4the arcs 56 of the auxiliary die sections merge with the cylindrical portions of the arcs of the dies I8 and 24 and describe a complete circular cylindrical pressing surface.

The dies I8 and 24, during operation, function in conjunction with a mandrel 62 which is positioned between said dies and extends outwardly at each end from the die cavity. That portion of the mandrel which is confined within the die cavity is of hollow construction, being provided with a zone 68 in 'which hot or cold,

liquid may be circulated to heat or chili the suriace'of the mandrel within the die cavity. The tubular wall 64 which defines the zone 63 carries at one end a plug 65 which functions as an endV closure for the zone 63. An extension 66 is joinedto the opposite end of the tube 64, said extension Y being provided with two parallel bores 61 and 68 pipe 69 and the mouth 12 thereof faces the wall of tube 64. A second pipe 13 is also threadedly carried at the end of extension 66 and projects into zone 68, the mouth 14 of said pipe being` positioned at the opposite end of the zone adjacent plug 65. Pipe 18 connects with pipe 16 in bore 68.

The arrangement is such that liquid or steam may be introduced and circulated through zone 63 to cool or heat the wall 64 which faces the dies I8 and 24 and auxiliary dies 55. The fluid may be introduced through pipe 10 and pipe 13 and discharged adjacent the far end of the zone 63, the fluid being withdrawn through pipes 1| and 69, or the fluid may be introduced through pipes 69 and 1I and withdrawn through pipes 13 and 16. In this manner. during a phase of heating or chilling the tube 64. the tube may be raised or lowered in temperature, as the case may be, in a uniform manner throughout its length.

- 6 through tubular projections 82. An annular groove is provided in the face of plug 18 circumscribing each projecting tube 82, said grooves being adapted to contain a suitable packing material 83. Packing glands 18 are receivable in the annular grooves and bear against the packing material 83 to form fluid-tight joints. VThe opposite ends of bores 86 and 6I are threaded to receive pipes 84 and 85, respectively.

The outer portion of the bushing 11 is provided with threads 86 which engage with threads 81 provided 'upon the interior Wall of yoke 88. The bushing 11 is flanged adjacent one end, as shown best at 89 in Fig. 11, said flange being provided with an offset shoulder 90 "which is adapted for engagement with the plug 19.

As has been hereinbefore described. the mandrel 62 is adapted to be positionedin the die cavity. However, said mandrel is supported only adjacent one end, to-wit, upon the yoke, the mandrel extending cantilever-fashion therefrom. To secure the mandrel in the yoke, the bushing 'l1 is first loosely threaded into the yoke; the plug 19 is then inserted in the bushing and subsequently the extension 66 is threaded in the bushing with the projecting tubes 82 of the plug engaging in the glands 18. With the bore 61 vertically above the bore 68, the bushing 11 and extension 66 are drawn together securely.

`'Iihe yoke 88 is supported by bars 9I which are, in turn, secured at their ends to blocks 92 which slidably embrace opposite tie-rods II. Struts 93 extend downwardly from bars 9| and are anchored upon blocks 94 on each side of the machine. Angular braces 95 extend from blocks 94 to points adjacent the ends' of bars 9|. Blocks 84 carry wheels 96 which bear against the tierods II which are embraced by the slidable blocks 92. A vertically movable supporting assembly is thus provided for the mandrel 62 whereby theI mandrel may be raised or lowered a limited distance as die i8 is raised or lowered. Stops 91 are mounted upon the tie rods I I to prevent excessive downward movement of the mandrel, to afford clearance between the mandreland die i8 and auxiliary dies 56 when the dies are open.

4lin employing the present invention, a pipe or tubeis adapted to be pressed between dies I8 and 24, auxiliary dies 56 and mandrel 62. erably the tube or pipe is constructed of paper or other fibrous material which carries a uniformly dispersed thermoplastic binder of the plastic or cold setting type. The binder may be dispersed throughout the thickness of the paper or fibrous material by saturation or impregnation, or the binder in discrete particle `form may be added to the paper or fibrous stock in the beater of the usual paper machine. Y

As a specific example, which however is not to be construed as a limitation, a web may' be formed upon the usual paper machine, the stock from which the web is made comprising fibrous material, and. extracted pine wood pitch treated with'a basic substance -comprising certain metal oxides or hydroxides, in accordance with the invention set forth in the copending application of Phillip Goldstein and' Harold R. Gillette. `Serial The extension 66, adjacent one end, is provided No. 258,577, filed February 25, 1939, or the web may be made in accordance with the teaching of the patent to Richter and Gillette, Patent No. 2,264,189. issued November 25, 1941.

For purposes ofthe present invention, the

web may be cut into suitable sheets, such as indicated at 98 in Fig. 10, and each sheet may be rolled upon itself to form a tube 99. the free and the mandrel.

to the adjacent edges |02, |08 of the area and that the edges |02 and |03 constitute the ends of the tube 90. Therefore, the thickness of the wall of the tube 99 adjacent one end is greater than the thickness of the tube llwall adjacent the opposite end. This difference in tube wall thickness is made forpurposes which will more clearly be brought out hereinafter. when beingrolled may be rolled upon a tapered mandrel whereby the inner diameter f the tube 'varies progressively throughout its length. Of

course, it is to be understood that the wall thickness gradient throughout the length of the tube `may be secured by expedients otherthan that hereinbefore described and, hence, the present invention is not to be limited to this detail.

The tube or pipe 99 is charged to the pressing machine by threading the same over mandrel 62.

Of course, the dies are in open position during the threading operation. The mandrel is slightly larger in diameter adjacent-theextenslon 06 than itis adjacent the plug 65 and tapers from one end to the other. By this provision the removal of the pipe, after pressing, is facilitated. The tube 08 is threaded onto mandrel 62 with the thinner-walled end adjacent the extension 66, or adjacent the portion of the mandrel of larger diameter. Hence, inasmuch as the surfaces of the dies are parallel, the thickness of the pipe compensates for the taper of the mandrel and when the pressingtakes place the wall of the pipe .will be subject to the same degree of pressure throughout its entire length. Hence, the pipe wall will be pressed to a substantially uniform density throughout. In addition, the tapered inner diameter of the preliminarlly rolled tube conforms with the taper of the mandrel-and assures a snug fit of the tube upon the mandrel.

After the pipe 09 has been mounted upon the mandrel 62, fluid under pressure may be introduced into the lower portions of cylinders, 8 and rams will move the lower die .I8 upwardly. As has been hereinbefore described, this movement causes the auxiliary dies 55 to move laterally inwardly. Eventually the press closes to the position shown in Fig. 6 at which time the entire wall of the pipe is pressed between the outer dies As will lbe hereinaftermore fully described, steam is introduced into the dies I8 and 24 through the respective pipes 48 connecting into each die. Simultaneously steam v may be introduced .into the mandrel through, for

instance, pipe 1 I. The pressing period with the simultaneous 4ap- I plication of heat is carried out for a sumcient length of time to cause the plastic binder carried by the fibrous material constituting the pipe walls to soften and flow. The pressure exerted upon the walls of the pipe 80 is sufficient to densify the wall structure and cause a 4ilow of the binder across the planes of contact of adjacent convolutions of the sheet material constituting the pipe 00. In this manner a pipejor tube is formed having a relatively dense wall'structure in which the binder isuniformly distributed. The flow of the binder between adjacent convolutions of the In addition, the tube to substantially the same temperature as the pressing surfaces of dies I8 and 24, the auxiliary dies being heated by their contact with the tan-- gential surfaces of the dies I8 and 24 as can bereadily seen from Fig. 6. In this manner the circumscribing dies transfer a substantially uniform amount of heat over the entire outer area of the pipe. f

After a predetermined period of pressing with u heat, the introduction of steam to the dies and mandrel is discontinued and cold Water isintroduced into the dies I8 and 24 through their respective inlet pipes 43, the water being discharged through the'respective drain pipes 48 so as to cause a circulation of water in the interior of lthe dies. Of course, by the provisiony of the bailles 38, the heat transfer of the steam or cold water passing through the dies is maintained at an ecient temperature differential between the ilud introduced and the iluid discharged from the dies. For efllcient operation the cooling water introduced into the die interiors may be employed as pre-heated feed-water for the steam boiler employed in conjunction with the machine. s

Of course,the introduction of the cooling medium to the dies I8 and 24 reduces the temperature ofthe outer portion of the tube or pipe being pressed. Hence, the binder is caused to set within the tube wall, the setting having its inception in the outer surfaceof the pipe and progressing inwardly. As a' feature of the present invention the average temperature of the pipe isl reduced an appreciable degree from its maximum temperature by the chilling of the outer dies prior to the vintroduction of cooling water to the interior of the mandrell 82. It has been found that if the mandrel and outer dies are chilled at av A substantially uniform rate, the pipe shrinks upon vthe mandrel and can 'only be removed therefrom ends of the dies 24 and I8 respectively. The in-y ner edges of said plates traverse the pressing surface of the dies. Said inner edges are chamfered as indicated at |00 (Fig. 8) and the edges of said plates extend beyond the pressing surfaces of the dies. During the pressing operation the chamfered edges of the plates |04 and |05 pinch the pipe 09 being 'pressed adjacent both ends thereof.

It has been found, when employing certain types of binders, for instance, the pine wood sheet constituting' the pipe renders the wall structure substantially homogeneous. The time necessary to cause the desired flow and densiflcation properties has been'found to'be sufficient to raise the temperature of the auxiliary dies Il pitch-zinc oxide binder hereinbefore described,

that a predetermined minimum moisture content must exist in the fibrous stock during th(` pressing'operation. Otherwise there is a tendency for the finished pipe to delaminate along the ,convolutions of the sheet comprising theplpe wall. By

the provision of the plates |04 and |05, the escape of the moisture during the heating and pressing operation is substantially prevented and the resulting pipe wall structure shows no tendency to delaminate.

Of course it is to be understood that with other types of binders this precaution may not be nec- 9 essary and, consequently, the plates |04 and |05 may or may not be used as desired.

A pair of supporting bars |01 may be mounted at one end upon the bars 9|, which project from the slidable blocks 92. The bars |01'converge toward each other away from the machine proper and terminate in two pair of parallel supports as shown at |08 in Fig. 4. A cylinder |09 is carried between the bars |01, said cylinder having pipe connections and at opposite ends thereof. The cylinder |09 is adapted to function as a hydraulic motor having a piston reciprocably positioned therein. A piston rod ||2 is connected to the piston and carries, externally of the cylinder, a cross head 3. A pair of connecting rods ||4 are secured adjacent opposite ends of the cross head ||3 and carry at their opposite ends a stripping ring 9. 'Ihe ring ||9 has an internalv diameter substantially equal to the external diameter of the extension '66, and said ring is adapted to be reciprocably m'ovable along the axis of the mandrel 62. l

After the pipe 99 has been suitably pressed and the binder has been set, the rams 5 are lowered thus lowering the die I8. During the pressing period the' mandrel is `essentially supported by the lower die I8, said mandrel being raised from the position shownin Fig. '1 to the position shown in Fig. 6. This upward movement of the mandrel is accommodated. by the movable supporting structure comprising the blocks 92, blocks 94 and associate structure. Accordingly when the die I8 moves downwardly, the mandrel 62 follows the lower die for a predetermined distance until the slidable blocks 92 contact the stops 91, at which time further downward movement of the mandrel is prevented while the die I8 moves to the position shown in Fig. 7.

In view of the fact that the cylinder |09 is carried by the same carriage which supports the mandrel, the cylinder moves downwardly with the mandrel` until the downward motion is prevented by the blocks 91. At this period fluid under pressure may be introduced into the cylinder |09 through the pipe I0 thereby projecting the stripping ring I|9 forwardly. The ring. ||9 abuts the end of the pipe and drives said pipe toward the free end of the mandrel, that is, the end which carries the plug `|55. It has been found that the stroke of the ring ||9 needonly be suiliciently long to move the pipe a relatively short distance along the length of the mandrel. Thereafter, the pipe can easily be removed by hand.

Referring particularly to- Fig. 7, it wil1 be noted that the downward movement of the die |8 is suiiicient, correlated with the position of the stops 91, to permit the connecting rods I I 4 which carry the ring 9, to pass into the die cavity without obstruction. After the ring ||9 has reached its outermost throw, fluid under pressure may be introduced into the cylinder |09 through the pipe I whereby the ring I9 may be retracted.

Referring particularly to Fig. 13, a diagrampipe |25 at one end, and atl-the other said pipe connects with the inlet pipes 43 to the dies I8 and 24. l

Pipe |25 connects into a flow reversing system |29 which comprises pipes |30 and |3|. lValves |32 and |33 are interposed in pipe |30, the other side of valve V|32 being connected to pipe |25. Valves |34 and |35 are connected in pipe |3|. Pipe 84, connected at one end to mandrel 62, is connected at its opposite end into pipe |3|, and pipe 85 also connected at one end to mandrel 62, is connected into pipe |30.

Valves |33 and |35 are connected with pipe |36 and valve |34 is connected with pipe |31.` The drain pipes 49 of dies I8 and 24 connect with'pipe |38 which is controlled by a back pressure relief'valve |39 which operates at about ten pounds per square inch pressure, and also by the die exhaust valve |40.4 Pipe |36 connects into pipe |38 on the atmospheric side of valve |39 and pipe |31 connects into pipe |38 on the pres-- sure side of valve |39. A pipe |4|, controlled by valve |42, connects at one end to pipe |38 on the high pressure side of valve |39zand at the other end to the aforesaid steam boiler feed water tank (not shown).

Valves |42 and |40 are preferably solenoidally operated. Valve |40 which is normally closed may be opened by push button control I 53 of the solenoid |49 or said solenoid may be controlled to open said valve bya float |50 which is responsive to the level of condensate from the dies which may accumulate in pipe |38. Valve |42 is also normally closed and the solenoid. |5| thereof may be energized to open the same when valve |23 is opened provided, however, the liquid iny the feed water tank |52 is below a predetermined level. vIf the liquid level in the feed water tank |52 is above said predetermined level, valve |42 will not open.

In carrying out the present process, a tube 99 constructed from a web made in accordance with the Goldstein and Gillette patent application, Serial No. 258,577 hereinbefore referred to, having a binder content 0f about 40%, an average wall thickness before pressing of about inch, a length of about 10 feet and an average internal diameter of about 2% inches, is threaded upon mandrel 62. With the assumption that a pressing cycle has just been completed, the dies will be at a temperature of about 100 F., when valve |2|iis initially opened. Valves |2|, |23 and |21- may comprise a 3-way valve wherein the opening of one valve closed the other two.

Steam at about 100 pounds per square inch crease in temperature.

Simultaneously with the introduction of steam into the dies I8 and 24, steam is also introduced .into the mandrel 62. At this phase of the opmatic showing of the piping system for the dies pipe |28, controlled by valve |21 connects pipe |25 to a source of air undera pressure of about70 pounds per square inch. Pipe |28 connects with eration valves |32 and I 35 are open and valves |33 and |34 are closed. Consequently steam passes through pipes |25, |30 and 84, and is introduced'into the interior of the mandrel via pipe 1| the steam discharging from the mandrel through pipe 13, pipe 85, pipe |3| and through the opened valve |35 to pipe I 38 and thence to the drain pipe |38 on the atmospheric side of, the back pressure valve |39. Shortly thereafter when the condensate has been blown from the mandrel, valve |35 is closed cutting off' communication with the drain pipe |38.

At the commencement of the pressing opera- 260 F. At this phase of the operation the binder in the pipe will have been softened to the extent where it is ready to ilow. The pressure upon the pipe is then increased to between about 900 to 1,000 pounds' per square inch and said pressure is maintained to theend of the pressing cycle.

When the dies have reached a temperature of about 275 F., the valve |32 is closed and valve |2| is closed and the valve |21 is opened to admit air to the system at about 70 pounds per square inch pressure which exhausts the steam from the dies and blows out the condensate through valve |40. Valves |32 and |35 being closed, the valve |23 is opened to admit water to the system at about 30 to 40 pounds per square inch pressure.

-In view of the fact, however, that valve |32 is closed the water passes only through the dies and consequently the dies cool at a relatively rapid rate cooling the exterior surface of the pipe 39. /The mandrel, not being connected to the water supply at this phase of the operation cools at a relatively lower rate and consequently the interior surface of the pipe 93 is at a considerably higher temperature than theexternal surface thereof.

When the dies have reached a temperature of about 140 on the cooling phase of the cycle,

valves |33 and |34 are opened. The water passing through the dies and discharging into pipe |38 then passes through pipe |31 at about l0 pounds pressure, the pressure at which the back pressure valve |39 is set. The water thus passes through valve |34 to pipe |3| and thence into pipe 85 and into the interior ofthe mandrel 62 via pipe 13. By introducing the water into the. mandrel via pipe 13, which is located at the lower portion of the zone 63 no steam or air pockets are permitted to form in the zone 63 since the mouth of the atmospheric side of valve |33.

When the temperature of the dies reaches about 115 F., valves |33 and |34 are closed andthe valves |32 and |35 are opened. In this manner the now of water through the mandrel is reversed, the water being introduced through the pipe 1| and being discharged through the pipe 13. Shortlythereafter, that is, when the temperatureof the dies reaches about 100 F., the press is opened and the pipe may be removed therefrom in the manner hereinbeiore described. The pressing cycle can then be repeated, it being the practice to immediately open valve |2| when the previously pressed pipe has been removed so that the dies and mandrel will have their temperature increasing when the next pipe is threaded upon the mandrel.

To support the free end of the mandrel while the pipe 38 is'being threaded upon or Aremoved -from the mandrel a pair of brackets |43 are mounted upon the endmost tie rods Il, said 12 arepositioned adjacent each side of the mandrel, the ends of said guides being flared outwardly.

Valves |32, |33, |34 and |33 may be automatically operated by means of solenoids |46 `and |41 connected by a linkage system |43 to the various valves. In view oi.' the fact, however, that these valves may be operated in any desired manner the useof the solenoids and connecting linkage vis not intended as a limitation of the present invention and per se does not constitute a part of the present invention. In view oi the fact that the mandrel is movable vertically, the pipes 34 and B5 are preferably of flexible construction.

It will be apparent that the machine comprising the present invention is particularly adaptable for making tubes, conduits or pipes fromflbrous materials, preferably in laminated sheet or strip form, which carry orhave been impregnated with a plastic binder. The machine is particularly suitable for operating upon nbrous materials having cold setting binders, although the same may be advantageously employed withthermo-setting or heat curable binders carried by the ilbrous stock.

' Although the preliminarlly formed pipe or tube is herein described as being made up of a brous sheetconvolutely wound, the preliminary tube may be wound of spirally wrapped strips or may comprise a relatively thick ilbrous'board 'wound as a single layer and joined along a longitudinal seam.

The process herein described is particularly suitable in pressing' fibrous pipes, tubes or conduits which are made up in multiple wall thicknesses, although the process also contemplates pressing a single-layered wall tube since the problem of joining the edges of single layered tube vto form a longitudinal seam is somewhat similar l 'to the problem of causing ply convolutions to adhere to each other. I

The pipe, tube or conduit which results from I press herein described may be so constructed as brackets carrying' a roller |44 upon which the plug-portion 65 of the mandrel rests. To facilitate lthreading of the pipe upon the mandrel lateral guides |45, mounted upon the brackets |43 to simultaneously press a plurality of pipes merely' by duplicating the dies and mandrel and having yall subjected to the pressure oi' one set of hydraulic rams. In addition, if desired the machine may be so disposedv as to have the rams acting laterally instead of vertically.

We claim as our invention:

1. A machine for pressing pipeV or conduit constructed of fibrous material carrying a plastic binder which comprises in combination, a frame, a plurality of dies carried by said frame, a mandrel positioned between said dies and adapted to carry a binder-carrying ilbrous pipe or conduit in enveloping relationv thereon, means for moving duit has been relieved.

structed of fibrous material carrying a plastic binder which comprises in combination, 'a frame, a plurality of dies carried by said frame, the surfaces of said dies being substantially parallel to' each other, a tapered mandrel positioned between said dies and adapted to carry a binder-carrying fibrous pipe or conduit inenveloping relation thereto, means for moving said dies relatively to each other to press and compact the walls of the Pipe or conduit upon thermandrel, means for heating said dies and mandrel to fuse the binder carried by said pipe or conduit whereby the pressure upon the walls thereof causes the binder to flow, means for chilling said dies and mandrel,

' and hydraulic means for moving said pipe or conduit longitudinally along said mandrel when the pressure upon the 4pipe or conduit is relieved. y

3. A machine for pressing pipe or conduit constructed of fibrousY material carrying a plastic binder which comprisesin combination, a frame, a stationaryupper die carried by said frame, a lower diecarried by said frame, means for moving said lower die vertically relatively to said upper die, a supporting carriage mounted for Vertical movement upon one end of said frame,a mandrel supported in cantilever fashion at one end upon `said carriage and positioned between said upper andlower dies, said mandrel being adapted to carry a binder-carrying fibrous pipe or conduit in enveloping relation thereon, means for moving said lower die upwardly to carry said mandrel and pipe or conduit into pressure contact with said upper die, means for heating said mandrel and dies to soften the binder carried by the pipe or conduit whereby the pressure upon the walls thereof lcauses the binder to iiow, andmeans' for chilling said dies and mandrel.

4. A machine for pressing pipe or conduit constructed of fibrous material carrying a plastic binder which comprises in combination, a frame, a stationary upper die carried by said frame, a lower die carried by said frame.- means for moving said lower die vertically relativelyto said upper die, a supporting carriage mounted for vertical movement upon one end of said frame, a

mandrel supported in cantilever fashion at one mandrel when the lower die has moved down- Wardly.

5. A machine for pressing pipe or conduit constructed of fibrous material carrying a plastic binder which comprises in combination. a frame, a stationary upper die carried by said frame, a lower die carried by said frame, means for moving said lower die vertically relatively to said upper die, a supportingcarriage mounted for vertical movement upon one end ofrsaid frame, a mandrel supported in cantilever fashion at one end upon .said carriage and positioned between said upper and lower dies, said mandrel being adapted to 'carry a binder-carrying fibrous pipe or conduit in enveloping relation thereon, means for moving said lower die upwardly to carry said mandrel and pipe or conduit into pressure contact with said upper die, means for' heating said mandrel and dies to soften the binder carried by the pipe lor conduit whereby the pressure upon the walls ythereof causes the binder to flow, means for chilling said dies and mandrel, and means for moving said pipe or conduit longitudinally on said mandrel when the lower die has moved downwardly, said means comprising a stripping ring circumscribing said mandrel, and pressure means mounted on said carriage for moving said ring into abutting relationship with an `end of saidl die, a pair of diametrically opposite side diesA having similar pressing surfaces carried by said second mentioned die, said side dies being movable diametrically with respect to each other and being movable parallel t0 the path of movement of said second mentioned die and relative'thereto, said side dies being moved by contact with the first two mentioned dies when said second mentioned die moves into pressing relationship whereby all of said dies simultaneously exert a pressing force upon the exterior of the tube or conduit.

7. In combination with a machine for pressing the walls of cylindrical pipe or conduit comprising a frame, a stationary die carried by said frame a portion of the surface ofwhich conforms with a portion ofthe cylindrical surface of the pipe or conduit, a diametrically disposed similar die movable diametrically with respect to said stationary die, a pair of diametrically opposite side dies having similar pressing surfaces carried by said second mentioned die, said side dies having cam surfaces at their rearfor contacting said first two mentioned dies when the second mentioned die moves into pressingl relationship with the stationary die, said side dies being movable diametrically inwardly toward each other when their cam surfaces contact said two first mentioned dies conduit.

' tioned dies, the cam surfaces of one pair of said 8. In combination with a machine for pressing Ythe walls of-cylindl'ical pipe or conduit comprising a frame. a pair oi' relatively movable primary dies supported in said frame, :a second intermediately positioned pair of dies movable in Vthe same relative direction as the primary dies and in a. direction transverse Vthereto upon being embraced thereby, each of said dies having similar arcuate pressing surfaces and being constructed and arranged to present a substantially continuous surfac to the outside of the pipe or conduit from the beginning to the end of the pressing cycle, coacting cam surfaces formed on each 'of l saiddies for moving said intermediately posidies being tangential to and forming continuations of said pressing surfaces, and a mandrel positioned between said dies to receive the pipe or conduit to be formed.

9.` In combination with a machine for pressing the walls of cylindrical pipe or conduit comprising a frame, a pair of relatively movable primary dies supported in said frame, a second intermediately positioned pair of 'dies movable in the same relative direction as the primary dies and in a direction transverse thereto upon being ernbraced thereby, each or said dies having similar l arcuate pressing surfaces and being constructed and arranged to present a substantially continuous surface to the outside of the Ipipe or conduit from the beginning tothe end of the pressing cycle, coacting cam surfaces formedgoneach of said dies for moving said intermediately posi-- tioned dies, the cam surfaces of said primary dies being tangential to and forming continuations of said pressing surfaces, means for moving said intermediately positioned dies out of pressing engagement with said pipe or conduit responsive to opening movement of said primary dies, and a 6 mandrel positioned between said dies to receive 

